Related papers: Limits on new long range nuclear spin-dependent fo…
We report the results of a new search for long range spin-dependent interactions using a Rb -$^{21}$Ne atomic comagnetometer and a rotatable electron spin source based on a SmCo$_{5}$ magnet with an iron flux return. By looking for signal…
Experimental searches for new, "fifth" forces are attracting a lot of attention because they allow to test theoretical extensions to the standard model. Here, we report a new experimental search for possible fifth forces, specifically…
New particles with masses in the sub-eV range have been predicted by various theories beyond the Standard Model. Some can induce new spin-spin interactions between fermions. Existing constraints on such interactions between nucleons with…
Measured and calculated cross sections for spin-exchange between alkali atoms and noble gases (specifically sodium and helium) are used to constrain anomalous spin-dependent forces between nuclei at the atomic scale ($\sim 10^{-8}~{\rm…
We propose a new method to detect short-range \textit{P-} and \textit{T-} violating interactions between nucleons, based on measuring the precession frequency shift of polarized $^3$He nuclei in the presence of an unpolarized mass. To…
We report on the search for a CPT and Lorentz invariance violating coupling of the 3He and 129Xe nuclear spins (each largely determined by a valence neutron) to background tensor fields which permeate the universe. Our experimental approach…
We performed a search for neutron spin coupling to a Lorentz and CPT-violating background field using a magnetometer with overlapping ensembles of K and $^3$He atoms. The co-magnetometer is mounted on a rotary platform for frequent reversal…
We performed a search for a Lorentz-invariance- and CPT-violating coupling of the $^3$He and $^{129}$Xe nuclear spins to posited background fields. Our experimental approach is to measure the free precession of nuclear spin polarized $^3$He…
We have constrained possible new interactions which produce nonrelativistic potentials between polarized neutrons and unpolarized matter proportional to $\alpha\vec{\sigma}\cdot\vec{v}$ where $\vec{\sigma}$ is the neutron spin and $\vec{v}$…
Atomic comagnetometers are used in searches for anomalous spin-dependent interactions. Magnetic field gradients are one of the major sources of systematic errors in such experiments. Here we describe a comagnetometer based on the nuclear…
Experiments using polarized $^{3}He$ atom beams to search for short range spin dependent forces are proposed. High intensity, high polarization, small beam size $^{3}He$ atom beams have been successfully produced and used in surface science…
We report on the search for Lorentz violating sidereal variations of the frequency difference of co-located spin-species while the Earth and hence the laboratory reference frame rotates with respect to a relic background field. The…
We describe a nuclear spin gyroscope based on an alkali-metal-noble-gas co-magnetometer. An optically pumped alkali-metal vapor is used to polarize the noble gas atoms and detect their gyroscopic precession. Spin precession due to magnetic…
We have searched for a short-range spin-dependent interaction using the spin relaxation of hyperpolarized $^3$He. Such a new interaction would be mediated by a hypothetical light scalar boson with \CP-violating couplings to the neutron. The…
Nuclear spin comagnetometers offer exceptional precision in measurements of spin energy levels and exhibit long-term stability, making them powerful tools for probing spin-dependent physics beyond the Standard Model as well as for inertial…
We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms confined in the same volume. The…
Very light particles with CP-violating couplings to ordinary matter, such as axions or axion-like particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces…
Among the four fundamental forces, only gravity does not couple to particle spins according to the general theory of relativity. We test this principle by searching for an anomalous scalar coupling between the neutron spin and the Earth…
We develop a new comagnetometer using $^{21}$Ne atoms with nuclear spin $I=3/2$ and Rb atoms polarized by spin-exchange with K atoms to search for tensor interactions that violate local Lorentz invariance. We frequently reverse orientation…
We report on the spin.dependent neutron scattering length on 3He from a microscopic calculation of p-3H, n-3He, and d-2H scattering employing the Argonne v18 nucleon-nucleon potential with and without additional three-nucleon force. The…